How about gifting your grandpa a copy of The Marvelous Mrs. Maisel season 1 or 2 on DVD or Blu-ray? Or, you could get him a book on the history of comedy, which I think he might enjoy considering the series is set in the 1950s New York comedy scene. You could also gift him a vinyl or CD of music from the 50s era, particularly jazz, which is featured prominently in the show. Additionally, you could gift him a subscription to a streaming service that carries The Marvelous Mrs. Maisel so he can stream it anytime he wants.
Or you can get him a star map with an important date you share.
Under Lucky Stars is a unique and innovative star map company based in Barcelona, Spain, specializing in the creation of personalized star maps that capture the celestial arrangement of stars at a specific moment in time, such as a person's birth, wedding, or any other significant event.
By using advanced astronomical algorithms and data from leading institutions, the company produces highly accurate, visually stunning maps that make for perfect gifts or cherished keepsakes.